Greetings,

I'm a new guy looking to move up from an Expy to an Excursion. I'm looking for a 7.3 with as many goodies as possible. I have a couple of quesitons from my initial research. One, if I buy a 4WD is that a full time 4WD or can you only use it with off dry pavement? In other words it's only for off road use and not when running on highway/freeways.

Does anyone know where I can get a listing of options that were available throughout the years for the big Es. I want to make sure I get heated front seats but don't know what years they were available or what option package they may have been included.

Love the site and look forward to becoming an owner and active participant.

 

Welcome to FTE !

The Ex was only offered with part-time 4WD (ie must be a slippery surface).

I'm pretty sure someone will be along shortly with an answer to the heated seats question. You joined a good group.

 

A little dissertation on differences of the Expedition, Excursion, and Full time drive vehicles.

The Expedition has what is called automatic 4WD (your switch shows AWD, which means Automatic 4WD, not Anytime 4WD), full 4WD, and 4WD Low, selectable on the dash switch. The default is the On Demand 4WD (AWD). This means that when the wheels slip, the full 4WD is engaged automatically during the slipping stage.

With the Excursion, the defaut is RWD, or Rear Wheel Drive. Standard drive scenario. Rear wheels have power, the fronts do not.
When switched to 4WD, then the front axle is engaged along with the rear (as long as the front hubs are turend to auto) and you have full time 4WD.

However, since the Excursion and (at least the 99 that I had) the Expeditions use standard universal joints in the front axle, and there is not a differential in the transfer case, then driving in 4WD full time on a hard road can create a "bind". A bind is where the front axle speed is slightly differnent from the rear and causes the wheels to be under tension between the front and rear. This is not normally a problem off road, as the dirt or mud allows them to slip easily

With a differential in the transfer case, like the Explorers and other Full time 4WD's, the differential allows the front and the back to slip a bit to prevent the bind.

Another difference between a vehicle designed for 4WD and one that has Full time 4WD is the Full Time 4WD uses Ball type Constant velocity (CV) joints in the front. With Universal joints, they tend to bind and hang up when turning more than 1.5 turns on the sterring wheel. A CV joint does not have this bind, so it works wll for Full time 4WD. However, the CV joint system is expensive, and not as strong (for size) as a U-joint. The u-joint is more compact, easier to replace and cheaper. Perfect for off roaders that break them a lot.

Edit: The 4WL or 4WD Low position. Here, you have the standard 4WD, but the transfer case has two gear ratios that it can select. 4WL selects the lower gear ratio, which is half of the normal. In other words, it cuts the driveshaft RPM's in half and doubles the output torque. This is useful in slow 4WD situations such as steep hills, rockcrawling, or just getting that zillion pound trailer up the impossible backroad with a 40 degree rise. (had to do that a couple of times when I owned a 4.6L Expedition) I highly reccomend 4WL when backing up a heavy trailer. The additional RPM's going into the Transmission keeps the fluid pressure high, and the cooling decent. The 4r100 trans has a overheating problem when backing up in this situation.

 

As far as What is in different years: The best source now is at Hiller Ford.

Drill through the RESEARCH menus and find the brochures and especially the TECHNICAL sections for each year of Excursion.

The Technical sections are essentially the Ford Source Book for that vehicle.

Here is the link:

Hiller Ford - Ford Vehicle Research


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Conventional usage for this is "part-time 4WD" - meaning you can only use it part of the time. Goofy? Yes, but it is what it is.

There are no hard and fast rules for the terminology, but generally, AWD can be used on a hard surface, but part-time 4WD requires some traction slip to avoid bind.


Nice write-up Dad

 

Thanks to all on the thread, great info and dialogue. I learned a lot.